I don't see this as being too much of a coincidence. How often does Jackson go to Austrailia? Probably two or three times a year. Plus, how often do any of the other members end up visiting on assignment? Out of the rest of them combined, probably an additional two or three times a year.
So, it's probably safe to say there's a GB member in Australia about six weeks a year and, due to them being used at the various conventions, most likely none of those weeks would overlap. We also have to consider that there was a two week overlap from when the ARC wanted to interview Jackson to when he showed up. All told, the odds that one of the GB would be available in any given two week period of the year is 29%. Or, just a hair under one in three.
Happy coincidence. Nothing too amazing or surprising about those odds.